Hey Guys, love the website. I have a 2003 CHevy Tahoe 5.3 Z Flex Fuel. Troube began with a CEL/SES light. Few days later Tahoe started idling rough, varying idle speed, and on cold start may die if left idling during warm up. On a cold start, I also notice occasional knock in the engine, and if I slightly rev engine or place in drive before waiting for engine to warm up, it is VERY apparent. At first, it would idle better after warm up, but now it idles rough regardless, however, the knock does go away after it is warmed up. Only codes it spit out are P0174, and P0171 bank 1 and 2 lean. I cleaned the MAF sensor, and didn't notice a significant change at all. Should I go after new MAF, new O2 sensors? Thanks for your help.
Shayne J. Benoit
Spring Cityl, Tennessee
Thursday, July 1st, 2021 AT 9:45 AM
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